Variable speed transmissions have been known from the early industrial age in which belt driven transmissions were common. An attempt was made to develop non-slip transmissions to improve efficiency and positive drive. Some early inventions used perforations and pin drive systems such as Reenstierna U.S. Pat. No. 889,333, Novak U.S. Pat. No. 1,036,690, and McNeel U.S. Pat. No. 1,416,567.
Groove and rib devices such as Moore U.S. Pat. No. 955,279 and Winter U.S. Pat. No. 3,075,397 were also designed to eliminate the non-slip aspect of belt driven transmissions.
More recent developments of non-slip transmissions includes such patents as Gogovitza U.S. Pat. No. 6,055,880, Denance U.S. Pat. No. 6,158,296, Magyari U.S. Pat. No. 6,338,692, and Olszewski U.S. Pat. No. 6,786,497.